The "atherosclerotic process" is, in fact, an ensemble of processes occurring at the cellular, physicochemical, biochemical, and biophysical level in the arterial intima. The purpose of this program is to identify as many of these fundamental processes as possible, establish which are relevant to those in man, and study these in great detail in the animal model, wherein the pertinent variables can be measured or controlled with a rigor not possible in man. A clear definition of the role of diet in the development of atherosclerosis in man is of utmost importance.